Air filters are well-known devices that are positioned within an airflow path to remove particulate matter (e.g., dust, pollen, mold, bacteria, and other debris) therefrom. At least one air filter element is commonly employed in a vehicle's air induction system. The air filter element prevents particulate matter from traveling downstream through the intake manifold and into the combustion chambers of the vehicle's internal combustion engine. Vehicular filter elements are typically rectangular panels, but may also assume other shapes (e.g., annular or conical shapes). Due to their desirable filtration properties and low cost, disposable paper-based filter elements are commonly utilized; however, other types of filter element may also be employed including disposable foam air filters and reusable/cleanable cotton air filters.
As it continues to trap particulate matter, the air filter element slowly saturates with debris, and airflow through the element becomes impeded or restricted. When the air filter element becomes fully saturated (or dirty), airflow therethrough is substantially restricted and a considerable decrease in downstream pressure results. When employed in a vehicular air induction system, a fully saturated filter element may negatively impact the performance of the internal combustion engine. For example, a restricted filter element may lead to diminished horsepower and fuel efficiency. It is thus important to replace the air filter element (or clean a reusable filter element) when the element becomes overly restricted or dirty. An air filter element typically requires replacement or cleaning when the restriction level reaches, for example, 10 inches of water vacuum.
Unfortunately, it is often cumbersome to determine if an air filter element requires replacement. A visual inspection may be performed, but is typically inconvenient, inaccurate for determining remaining air filter life, and may require the services of a mechanic. Changing the air filter element after the accumulation of a certain number of miles (e.g., during each oil change) may result in the premature replacement of relatively clean filter elements or the overdue replacement of dirty filter elements.
Devices have been developed that may be installed in a vehicle's air induction system to monitor the restriction level of the air filter element; however, the installment of additional hardware increases vehicle part count and incurs additional cost. Furthermore, such filter monitoring devices are typically installed within a vehicle's engine compartment and typically require visual inspection to determine if the air filter element should be replaced.
Considering the foregoing, it would be desirable to provide a method and system for monitoring the restriction level of a vehicle's air filter element that may be performed by an onboard processor without the requirement of additional hardware. It would also be desirable if such a method and system provided an indication within the vehicle's passenger compartment when a filter element should be replaced. Finally, it would be desirable if such a method and system were to provide additional information relating to the status of the air filter element, such as remaining filter element life. Other desirable features and characteristics of various embodiments of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.